function List(name) {
    this.name = name;
    this.next = null;
}

function findCommonNode(headA, headB) {
    while (headA !== headB) {
        headA = headA == null ? headB : headA.next
        headB = headB == null ? headA : headB.next
    }
    return headA
}

// 循环 不够的时候拼一下